Rare gum rises from Black Saturday ashes

A species of eucalyptus heading for extinction has risen from the ashes of the Black Saturday bushfires.

A RARE SPECIES OF gum tree that five years ago faced extinction has been resurrected by one of the most destructive natural disasters in Australia's history - the Black Saturday bushfires.

While the 2009 fires caused great destruction to lives and property, the flames were a saving grace for the rare Buxton silver gum (Eucalyptus crenulata).

A survey of the gums in 2005 found the species - which inhabits only two sites in Australia, both north of Melbourne - was failing to regenerate in the wild.

But after the Black Saturday bushfires swept through, razing the 17-hectare Buxton Silver Gum Reserve, set up in 1978 near Marysville, the gum's hardy secrets were revealed.

A significant amount of topsoil was burnt in the fires, exposing the tree's large underground lignotubers - nutrient-rich stems - which were previously unknown because the trees had only been examined above ground.

Resilience of rare Australian gum

The Parks Victoria ranger in charge of the Buxton Silver Gum Reserve, Julie Flack, says the discovery pointed to the trees' longevity.

"That's an indication that those trees may be many hundreds of years old," she says, adding that the gums can seed or sprout from the lignotubers.

Four months after the fires in June 2009 the gums were sprouting fresh foliage. The reserve also flooded for the first time in 14 years last September, creating ideal conditions for regeneration.

"What's become apparent since the 2009 fires is that the fire and flood has absolutely triggered some really good results," Julie says.

She says it is now known that the species requires fire - and an extremely severe, hot one at that - and flood to survive. But what it doesn't need is another fire before the reserve has had time to recuperate.

Ensuring the seeds are planted to protect native gums

"We're hoping the trees will set viable seeds before we have another fire event," she says.

Work is also being done at the reserve between Taggerty and Buxton to control other threats to the gums, including a native parasitic climber, cassytha, and grazing by rabbits, wombats and wallabies.

"Just to survive is not necessarily good enough, it needs to thrive," Julie says. "That's why we need to remove the threats".

Further surveys will be carried out next month and in another five years' time to track the species' progress.

The Buxton silver gum also grows in the wild at Yering, in the Yarra Valley, and is a popular ornamental for gardens.